1. Field of the Invention
This invention relates to a vane compressor, and more particularly to a vane compressor having component parts which are unitized so as to reduce the total number of component parts of the vane compressor, and dispense with sealing portions conventionally arranged between the component parts which are unitized according to the present invention.
2. Description of the Prior Art
Conventionally, a vane compressor as shown in FIG. 1 is proposed e.g. by Japanese Laid-Open Patent Publication (Kokai) No. 3-18683, which is comprised of a cam ring 801, a front side block 803 and a rear side block 804 secured to opposite ends of the cam ring 801, a rotor 802 rotatably received within the cam ring 801, a front head 805 and a rear head 806 respectively secured to outer ends of the side blocks 803, 804, and a drive shaft 807 for rotating the rotor 807. The drive shaft 807 is rotatably supported by bearings 808, 809 arranged in the side blocks 803, 804, respectively.
Recently, aluminum or aluminum alloy (hereinafter both referred to as "aluminum-based metal") is widely employed as a material of the main component parts of compression mechanism of the vane compressor, such as the cam ring 801 and the front side block 803, to reduce the weight of the compressor.
Further, sealing members, such as O-rings, are interposed between the cam ring 801 and the front side block 803, between the cam ring 801 and the rear side block 804, between the front side block 803 and the front head 805, between the rear side block 804 and the rear head 806, to ensure air-tightness of the vane compressor.
These main component parts of the compression mechanism of the conventional vane compressor including the cam ring 801, the front side block 803, the rear side block 804, the front head 805 and the rear head 806 are separately formed by casting. When all these component parts are made of aluminum-based materials, the manufacturing costs of the vane compressor are increased due to the cost of the aluminum-based materials, and additional surface-treatments required to be provided on the component parts formed of these materials.
Further, when these component parts are formed separately, the number of component parts of the compressor is increased to increase the whole size of the compressor and also the number of sealing members to be provided between these component parts is increased to increase the number of portions susceptible to possible leaks.